In certain machines, tie rods are used to connect two different components together. In an automobile, for instance, a tie rod can be used to connect between a steering box or rack and pinion unit and a wheel steering arm, or between two wheels, among other things. Such tie rods have connectors on one or both ends for connecting to the various components. Such connectors can be in the form of heim joints or tie rod ends that are attached to the tie rod with a threaded connection. In a typical example, the tie rod is tubular and includes an internal threaded bore at one or both ends to receive an externally threaded portion of a connecting component, such as a heim joint or tie rod end. This threaded connection not only connects the connecting component to the tie rod, it also allows the positioning of the connecting component to be adjusted with respect to the tie rod by threading the connecting component in or out of the tie rod, thus altering the effective length of the assembly. As is known, a jam nut threaded onto the threaded portion of the connecting component can be threaded down against the tie rod to lock the two components in the adjusted position. As is also known, this adjusting mechanism can be used in an automobile to adjust toe-in of the wheels, for example.
In a typical example as shown in FIG. 1 (Prior Art), a tie rod assembly 10 has an inboard end 12 and an outboard end 14. The inboard end 12 connects to the steering rack and pinion unit and the out board end 14 connects to the wheel steering arm. The assembly 10 includes a tie rod 16 having axial threaded bores 18 and 20 (see FIG. 2) at the inboard and outboard ends, respectively. An inboard connecting component 22 is threaded into the threaded bore 20 and an outboard connecting component 24 is threaded into the threaded bore 20. An inboard jam nut 26 is threaded onto the inboard connecting component 22 and can be tightened down against the tie rod 16 to lock the connecting component 22 with respect to the tie rod 16, in a known manner. An outboard jam nut 28 is similarly threaded onto the outboard connecting component 24. The inboard connecting component 22 and the outboard connecting component 24 are not threaded the same. Rather, one is threaded with a right hand thread and the other is threaded with a left hand thread. In this manner, the length of the tie rod assembly 10 can be altered to adjust toe-in without disconnecting either connecting component 22, 24 from its respective steering component. All that must be done is to loosen each of the jam nuts 26, 28 and rotate the tie rod 16 in the desired direction. Because of the different handed threads on the two connecting components 22, 24 and respective axial bores 18, 20, rotating the tie rod 16 in one direction will simultaneously thread the two connecting components 22, 24 into the tie rod 16, thus shortening the tie rod assembly 10, and rotating the tie rod 16 in the other direction will simultaneously thread the two connecting components 22, 24 out of the tie rod 16, thus lengthening the tie rod assembly 10. Upon completion of the toe-in adjustment, the two jam nuts 26, 28 are locked onto the tie rod 16 to maintain the adjustment.
In a typical racing car, the steering geometry may be changed several times for one race to find the best combination for the particular track and race conditions. Therefore, it is important that such adjustments can be made quickly and easily. With a tie rod assembly 10 on a typical stock car type race car, the outboard jam nut 28 can be accessed without jacking up the vehicle but the inboard jam nut 26 cannot readily be accessed without jacking up the vehicle. Thus, to adjust toe-in on such a vehicle, the vehicle is typically jacked up to loosen the inboard jam nut 26, the outboard jam nut 28 is loosened, the vehicle is lowered so that the toe-in can be adjusted by rotating the tie rod 16 in the desired direction as described above, the vehicle is jacked up again so that the inboard jam nut 26 can be locked down, the outboard jam nut 28 is locked down and the vehicle is lowered again. This is time consuming and prevents rapid adjustment of the toe-in.
It is an object of this invention to provide a tie rod assembly that does not require a vehicle to be jacked up to adjust toe in.
It is a further object of this invention to provide a tie rod assembly where an inboard jam nut can be loosened and tightened from an outboard position on the vehicle.
It is a further object of this invention to provide a tie rod assembly where the inboard jam nut can be loosened and tightened from a position proximal an outboard jam nut.
It is a further object of this invention to provide an inboard jam nut that can be loosened and tightened from a position proximal an outboard jam nut of a tie rod assembly.